To give you an almost answer just off the top of my head, most plants that have stripes like that are the result of a viral mutation at some point. Take for instance, the variegated leaves on privet, euonymus, etc. I don't know for sure on the camellias, but it would something interesting to research. One of those things that you just never know when you might want to know it. Anyway, absolutely nothing to worry about. As a matter of fact, almost all varieties that are not true species plants came about that way, except those bred for certain characteristics. Which, in this case, could have been a cross between a red and a white, trying to get a different pink.
I should go now!
If it's worth doing, it's worth doing right. If you wouldn't put your name on it, it ain't done right!